Endangered North Atlantic Right Whale Population Shows Slight Increase In Latest Estimate

The population of critically endangered North Atlantic right whales has shown a slight increase, according to the latest estimate released Tuesday by the North Atlantic Right Whale Consortium.

The newly released estimate pegs the global population of North Atlantic right whales at 372 individuals, including 12 calves born in 2023, in what the consortium described as a "heartening" increase since the population dipped to 358 four years ago.

“To see the population estimate increasing gives us hope that what felt like a free fall over the past decade may be behind us,” said Heather Pettis, a research scientist at the Anderson Cabot Center and the chair of the North Atlantic Right Whale Consortium. “While we still have a great deal of work to do to ensure that this species not only recovers but thrives, it feels really good to be able to share a little bit of positive news.”

The latest estimate was included in a report being released at the Consortium’s annual meeting this week in Providence, Rhode Island.

The group emphasized, however, that the species is still facing "significant ongoing threats" from human activities and that entanglements and ship strikes remain the leading causes of right whale fatalities. 

The good news on the population estimate was tempered by concerning reports on how right whales have died.

So far in 2024, there have been five detected right whale deaths and four other lost calves, the highest annual mortality count since 2019, according to the Consortium. Causes of death were identified as chronic entanglement for one whale and vessel strikes for three. One of the whales could not be retrieved for assessment. These nine deaths may well lower the population estimate for 2024 when that is generated next year.

“While entanglements remain the leading cause of death and injury, this year there were at least six vessel strike-related injuries/deaths, highlighting the importance of addressing this issue soon," Pettis said. "The persistent aggregation of more than 50 right whales in the New York shipping lane this summer underscores this even further."

While some groups, including the Nantucket-based ACK For Whales, believe the ongoing development of offshore wind energy facilities along the East Coast is another cause of whale mortality, the National Oceanic and Atmospheric Administration (NOAA) has stated "At this point, there is no scientific evidence that noise resulting from offshore wind site characterization surveys could potentially cause whale deaths. There are no known links between large whale deaths and ongoing offshore wind activities."

In its new report, the Consortium details several of the 2024 mortalities that it says highlight the nature of human-caused injuries to right whales. A three-year-old female who was entangled for more than 17 months was malnourished and had rope deeply embedded in her tail when she was found dead in January 2024. Right whale #1950, a female who was at least 35 years old and had given birth to her sixth calf this year, died from a vessel strike in March 2024. Her dependent calf is presumed dead. 

The 2024 calf of right whale “Juno” (#1612) was struck by a vessel sometime between December 9, 2023, and January 3, 2024, and suffered significant propeller cuts to her head. Disfigured and observed bleeding on multiple occasions, the calf was last sighted alive on February 27, 2024. On March 2, 2024, Juno was sighted without her calf, and the calf was found deceased the next day.

In addition to the five documented mortalities and four lost calves, to date, analysis by the Aquarium’s Anderson Cabot Center scientists reveals 13 human-caused injuries to right whales in 2024, including seven fishing gear entanglements with attached gear, four entanglement injuries (with no attached gear), and two vessel strikes.

“After seven years of steady decline from 2013 to 2020, this reversal in the trend of the population over the last few years is welcome news," said Philip Hamilton, senior scientist at the New England Aquarium’s Anderson Cabot Center and the identification database curator for the Consortium. "I wish we could infer that this paints a rosy picture for the future, but the 2024 mortalities and serious injuries are sobering. While the whales may be adapting to a rapidly changing environment, the continued high level of mortality and serious injury clearly shows we must continue to adapt and evolve our management.”

The Consortium stated that efforts to protect North Atlantic right whales include advances in ropeless or “on-demand” fishing technology. But while that technology has shown promise, "widespread implementation will require significant financial support to escalate the manufacturing of the gear and provide training and support for the fishing industry to adopt gear use."

NOAA has also been working to develop vessel speed restrictions that have proven controversial up and down the East Coast, including on Nantucket, where local and state officials are pushing back on speed restrictions for Nantucket Sound that would affect the island's ferry transportation.

Calving numbers in this decade have improved over those in the 2010s but are still below what scientists saw in the 2000s. This past calving season, 20 calves were born—eight more than last year, but that increase was greatly diminished by the deaths of at least five of those calves by spring. Four of the mothers calved for the first time, which is encouraging given that many adult females have been delaying their first calving in recent years.

“The 2024 calving year was an emotional roller coaster ride for those of us in the right whale community, with relatively high numbers of births and deaths," Hamilton said. "It ended on a high note with a mother named Pico (#3270) detected with a calf in June offshore of Virginia. We approach the upcoming 2025 calving season (starting December 2024) with both excited anticipation and concern. One big question is whether some of the 40+ adult females between the age of 10 and 20 that have delayed giving birth to their first calf will enter the breeding pool."